δῠσ-,
insepar. Prefix, opposed to εὖ, un-, mis-, with notion of hard, bad, unlucky, etc., as δυσήλιος, δύσαγνος; destroying the good sense of a word, or increasing its bad sense: hence, joined even to words expressing negation, as δυσάμμορος, δυσανάσχετο; poetry in strong contrasts, as Πάρις Δύσπαρις, γάμος δύσγαμος. Before στ, σθ, σπ, σφ, σχ, the final ς was omitted, see δυστ-. (Cf. Sanskrit du[snull]-, dur-, e.g. durmanās, ={δυσμενής}; ONorse tor-, e.g. torsóttligr (δύσμαχος); OIr. du-, do-, e.g. dochruth 'misshapen'.)